Internet telephony refers to communications services - voice, facsimile, and/or voice-messaging applications - that are transported through the internet, rather than the public switched telephone network (PSTN). The protocol used with e-phone is VOIP (Voice over internet protocol).
Internet telephony products are sometimes called IP telephony, Voice over the Internet (VOI), or Voice over IP (VOIP) products. Internet telephony is broken down into three main categories consisting of PC-to-PC telephony, PC to Phone, and Phone to Phone.
Some advantages of it are:
- Full scalability
- Lower cost
- Advance features
- Excellent voice quality